Package structure and package process of light emitting diode

Abstract

A light emitted diode (LED) package structure and an LED package process are provided. The LED package structure comprises a carrier, a spacer, at least one LED chip, a junction coating, a plurality of phosphor particles, and an encapsulant. The spacer is disposed on the carrier and provided with a reflective layer covering a top surface of the spacer. The LED chip is disposed on the reflective layer and electrically connected to the carrier. The junction coating is disposed over the spacer and covers the LED chip. The phosphor particles are distributed within the junction coating. The encapsulant is disposed on the carrier and encapsulates the LED chip, the spacer and the junction coating. Uniform light output and high illuminating efficiency can be obtained by the phosphor particles uniformly distributed in the junction coating. The junction coating is formed by package level dispensing process to reduce the fabrication cost.

1. A light emitting diode (LED) package structure, comprising:
 a carrier; 
 a spacer, disposed on the carrier, wherein the spacer is provided with a reflective layer covering a top surface of the spacer; 
 at least one LED chip, disposed on the reflective layer and electrically connected to the carrier, wherein the LED chip has a first electrode and a second electrode both disposed on a top surface of the LED chip, while the first electrode and the second electrode are respectively electrically connected to the carrier via a first bonding wire and a second bonding wire; 
 a junction coating, disposed over the spacer and covering the LED chip; 
 a plurality of phosphor particles, distributed within the junction coating; and 
 an encapsulant, disposed on the carrier and encapsulating the LED chip, the spacer and the junction coating. 
 
     
     
       2. The LED package structure according to  claim 1 , wherein the carrier comprises a metal leadframe, a pre-molded metal leadframe or a ceramic substrate. 
     
     
       3. The LED package structure according to  claim 1 , wherein the carrier has a cavity accommodating the spacer, the LED chip and the junction coating. 
     
     
       4. The LED package structure according to  claim 3 , wherein the cavity is filled with the encapsulant, while a top surface of the encapsulant is coplanar with a top surface of the carrier surrounding the cavity. 
     
     
       5. The LED package structure according to  claim 1 , wherein a profile of the encapsulant is in a convex lens shape. 
     
     
       6. The LED package structure according to  claim 1 , wherein the top surface of the spacer is fully covered by the reflective layer. 
     
     
       7. The LED package structure according to  claim 1 , wherein the top surface of the spacer is patterned or textured for enhancing light extraction efficiency of the LED package structure. 
     
     
       8. The LED package structure according to  claim 1 , wherein a top surface of the junction coating is patterned or textured for enhancing light extraction efficiency of the LED package structure. 
     
     
       9. The LED package structure according to  claim 1 , wherein the junction coating is made of transparent polymer or translucent polymer. 
     
     
       10. The LED package structure according to  claim 1 , wherein the junction coating is mixed with an organic filler or an inorganic filler. 
     
     
       11. The LED package structure according to  claim 10 , wherein a material of the filler within the junction coating is selected from a group consisting of SiO2, TiO2, Al2O3, Y2O3, carbon black, sintered diamond powder, asbestos, glass, and a combination thereof. 
     
     
       12. The LED package structure according to  claim 1 , wherein the encapsulant is made of transparent polymer or translucent polymer. 
     
     
       13. The LED package structure according to  claim 1 , wherein the encapsulant is mixed with an organic filler or an inorganic filler. 
     
     
       14. The LED package structure according to  claim 13 , wherein a material of the filler within the encapsulant is selected from a group consisting of SiO2, TiO2, Al2O3, Y2O3, carbon black, sintered diamond powder, asbestos, glass, and a combination thereof. 
     
     
       15. The LED package structure according to  claim 1 , wherein a size of the spacer ranges from 1.1 times the size of the LED chip to 3 times the size of the LED chip. 
     
     
       16. The LED package structure according to  claim 1 , wherein a material of the phosphor particles is elected from a group consisting of (YGdTb) 3 (AlGa) 5 O 12 :Ce, (SrBaCaMg) 2 SiO 4 :Eu, (Sr,Ba,CaMg) 3 SiO 5 :Eu, CaAlSiN 3 :Eu, CaScO 4 :Ce, Ca 10 (PO 4 )FCl:SbMn, M 5 (PO 4 ) 3 Cl:Eu, BaBg 2 Al 16 O 27 :Eu, Ba, Mg 2 Al 16 O 27 :Eu, Mn, 3.5MgO.0.5MgF 2 .GeO 2 :Mn, Y 2 O 2 S:Eu, Mg 6 As 2 O 11  : Mn, Sr 4 Al 14 O 25 :Eu, (Zn, Cd)S:Cu, SrAl 2 O 4 :Eu, Ca 10 (PO 4 ) 6 ClBr:Mn, Eu, Zn 2 GeO 4 :Mn, Gd 2 O 2 S:Eu, La 2 O 2 S:Eu, wherein M is an alkali earth metal selected from a group consisting of Sr, Ca, Ba, Mg, and a combination thereof. 
     
     
       17. A light emitting diode (LED) package structure, comprising:
 a carrier; 
 a spacer, disposed on the carrier, wherein the spacer is provided with a reflective layer covering a top surface of the spacer, and the top surface of the spacer is patterned or textured for enhancing light extraction efficiency of the LED package structure; 
 at least one LED chip, disposed on the reflective layer and electrically connected to the carrier; 
 a junction coating, disposed over the spacer and covering the LED chip; 
 a plurality of phosphor particles, distributed within the junction coating; and 
 an encapsulant, disposed on the carrier and encapsulating the LED chip, the spacer and the junction coating. 
 
     
     
       18. The LED package structure according to  claim 17 , wherein the LED chip has a top electrode electrically connected to the carrier via a bonding wire and a bottom electrode electrically connected to the carrier via the spacer. 
     
     
       19. A light emitting diode (LED) package structure, comprising:
 a carrier; 
 a spacer, disposed on the carrier, wherein the spacer is provided with a reflective layer covering a top surface of the spacer; 
 at least one LED chip, disposed on the reflective layer and electrically connected to the carrier; 
 a junction coating, disposed over the spacer and covering the LED chip, wherein a top surface of the junction coating is patterned or textured for enhancing light extraction efficiency of the LED package structure; 
 a plurality of phosphor particles, distributed within the junction coating; and 
 an encapsulant, disposed on the carrier and encapsulating the LED chip, the spacer and the junction coating. 
 
     
     
       20. The LED package structure according to  claim 19 , wherein the LED chip has a top electrode electrically connected to the carrier via a bonding wire and a bottom electrode electrically connected to the carrier via the spacer.